Energy in Chemical Reactions

E_{a is a symbol of?}

• Heat energy

• activation energy

• kinetic energy

• light energy

What instrument would you use to detect an endothermic or exothermic reaction?

• Ruler

• Thermometer

• Kalimeter

• balance

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

What type of reaction is this?

• endothermic

• combustion

• hydrocarbon

• exothermic

Tags

NGSS.HS-PS1-4

What kind of reaction is shown in the image?

• endothermic

• exothermic

• combustion

Tags

NGSS.HS-PS1-4

True or false: ΔH for an endothermic reaction is a positive value.

• True

• False

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-1

Cooking an egg is example of?

• endothermic reaction

• exothermic reaction

• covalent bond

• none of these

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-4

During a chemical reaction, from where is the energy stored or released?

• The atoms

• The protons in the nucleus

• The nucleus

• The bonds between atoms

Tags

NGSS.HS-PS1-4

Students are challenged to design cold packs for treating injuries. To do this they must find a chemical reaction that absorbs heat energy. The ideal chemical reaction will reach a temperature in the range of 0°C to 4°C and maintain that temperature for a minimum of 20 minutes.

(See attached Table)

Based on the information provided in the table, and a room temperature of 25°C, which reaction best fits the criteria of the design challenge?

• 1

• 2

• 3

• 4

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-4

Meals-ready-to-eat (MREs) are packaged meals that include their own disposable heat pack to warm the food. Students are challenged to duplicate MREs in the science classroom using chemical reactions. The final product must be safe and light. Based on the observations, which chemical reaction would be the best choice for making a heat pack?

• 1

• 2

• 3

• 4

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-4

In a certain chemical reaction, Reactant 1 and Reactant 2 release thermal energy. Students collect data by measuring the temperature change produced by adding increasing amounts of Reactant 2 to 25 grams of Reactant 1. They graph the data. (See attached graph) Students must design a device that uses 25 grams of Reactant 1 and produces the maximum amount of heat with the smallest amount of Reactant 2. How much of Reactant 2 should they use to meet the criteria of the design challenge?

• 10 grams

• 15 grams

• 20 grams

• 25 grams

Tags

NGSS.HS-ETS1-3